<template>
  <div class="article-container">
    <!-- 导航栏 -->
    <van-nav-bar
      class="page-nav-bar"
      @click-left="$router.back()"
      left-arrow
      title="黑马头条"
      fixed
    ></van-nav-bar>
    <!-- /导航栏 -->

    <div class="main-wrap">
      <!-- 加载中 -->
      <div v-if="loading" class="loading-wrap">
        <van-loading color="#3296fa" vertical>加载中</van-loading>
      </div>
      <!-- /加载中 -->

      <!-- 加载完成-文章详情 -->
      <div v-else-if="article.title" class="article-detail">
        <!-- 文章标题 -->
        <h1 class="article-title">{{ article.title }}</h1>
        <!-- /文章标题 -->

        <!-- 用户信息 -->
        <van-cell class="user-info" center :border="false">
          <van-image
            class="avatar"
            slot="icon"
            round
            fit="cover"
            :src="article.aut_photo"
          />
          <div slot="title" class="user-name">{{ article.aut_name }}</div>
          <div slot="label" class="publish-date">
            {{ article.pubdate | relativeTime }}
          </div>

          <!--
             模板中 $event 的是事件参数
             当我们传递给子组件的数据既要使用还有修改
              传递: props
                :is-followed="article.is_followed"
              修改: 自定义事件
                @update-is_followed = "article.is_followed = $event"
              简写方式: 在组件上使用 v-model
                value="article.is_followed"
                @input="article.is_followed = $event"
              如果需要修改 v-model 的规则名称，可以通过子组件的 model 属性来配置修改
              一个组件上只能使用一次 v-model
              如果有多个数据需要实现类似于 v-model 的效果，咋办？
              可以使用属性的 .sync 修饰符。
           -->
          <follow-user
            class="follow-btn"
            :isFollowed.sync="article.is_followed"
            :user-id="article.aut_id"
          ></follow-user>

          <!-- <van-button
            v-if="article.is_followed"
            :loading="btnLoading"
            class="follow-btn"
            round
            size="small"
            @click="onFollow"
          >已关注</van-button>
          <van-button
            v-else
            :loading="btnLoading"
            class="follow-btn"
            type="info"
            color="#3296fa"
            round
            size="small"
            icon="plus"
            @click="onFollow"
          >关注</van-button > -->
        </van-cell>
        <!-- /用户信息 -->

        <!-- 文章内容 -->
        <!-- v-html="article.content" -->
        <div
          class="article-content markdown-body"
          ref="article-content"
        ></div>
        <van-divider>正文结束</van-divider>

        <!-- 评论列表组件 -->
        <comment-list
        :sourceId="article.art_id"
        :list="commentList"
        @onload-success="onloadSuccessFn"
        ></comment-list>
        <!-- /评论列表 -->

        <!-- 发布评论 -->
        <van-popup
           v-model="isPostShow"
           position="bottom"
        >
          <comment-post
            :target="article.art_id"
            @post-success="onPostSuccess"
          ></comment-post>
        </van-popup>

      </div>
      <!-- /加载完成-文章详情 -->

      <!-- 加载失败：404 -->
      <div v-else-if="errStatus === 404" class="error-wrap">
        <van-icon name="failure" />
        <p class="text">该资源不存在或已删除！</p>
      </div>
      <!-- /加载失败：404 -->

      <!-- 加载失败：其它未知错误（例如网络原因或服务端异常） -->
      <div v-else class="error-wrap">
        <van-icon name="failure" />
        <p class="text">内容加载失败！</p>
        <van-button class="retry-btn" @click="loadArtcileInfo"
          >点击重试</van-button
        >
      </div>
      <!-- /加载失败：其它未知错误（例如网络原因或服务端异常） -->
    </div>

    <!-- 底部区域 -->
    <div class="article-bottom">
      <van-button class="comment-btn" type="default" round size="small" @click="isPostShow = true"
        >写评论</van-button
      >
      <van-icon name="comment-o" :badge="totalCommentCount" color="#777" />

      <!-- 收藏组件 -->
      <collect-article
      v-model="article.isCollected"
      :article-id="article.art_id"
      ></collect-article>

      <!-- 点赞组件 -->
      <like-article
      v-model="article.attitude"
      :articleId="article.art_id"
      ></like-article>

      <van-icon name="share" color="#777777"></van-icon>
    </div>
    <!-- /底部区域 -->
  </div>
</template>

<script>
import { getArticleByIdAPI } from '../../api/index.js'
import { ImagePreview } from 'vant'
import FollowUser from '../../components/follow-user.vue'
import CollectArticle from '../../components/collect-article.vue'
import LikeArticle from '../../components/like-article.vue'
import CommentList from './components/comment-list.vue'
import CommentPost from './components/comment-post.vue'
export default {
  name: 'ArticleIndex',
  components: {
    FollowUser,
    CollectArticle,
    LikeArticle,
    CommentList,
    CommentPost
  },
  props: {
    articleId: {
      type: [Number, String],
      required: true
    }

  },
  data () {
    return {
      article: {}, // 文章详情
      loading: true, // 加载中的loading 状态
      errStatus: 0, // 失败的状态码
      btnLoading: false,
      totalCommentCount: 0,
      isPostShow: false,
      commentList: [] // 评论列表
    }
  },
  computed: {},
  watch: {},
  created () {
    // 获取文章详情
    this.loadArtcileInfo()
  },
  mounted () { },
  methods: {
    onloadSuccessFn (total) {
      this.totalCommentCount = total
    },
    async loadArtcileInfo () {
      // 展示loading
      this.loading = true
      try {
        const { data: res } = await getArticleByIdAPI(this.articleId)
        this.article = res.data

        // 初始化图片点击预览
        // console.log(this.$refs['article-content'])
        setTimeout(() => {
          this.previewImage()
        }, 0)
        // 请求成功, 关闭loading
      } catch (error) {
        if (error.response && error.response.status === 404) {
          this.errStatus = 404
        }
        this.$toast('获取失败')
      }
      // 无论成功还是失败,都需要关闭loading
      this.loading = false
    },
    previewImage () {
      // 得到所有的 img 节点
      const articleContent = this.$refs['article-content']
      const imgs = articleContent.querySelectorAll('img')
      // 获取所有 img 地址
      const images = []
      imgs.forEach((img, index) => {
        images.push(img.src)
        // 给每个 img 注册点击事件，在处理函数中调用预览
        img.onclick = () => {
          ImagePreview({
            // 预览的图片地址数组
            images,
            // 起始位置，从 0 开始
            startPosition: index
          })
        }
      })
      // console.log(images)
    },
    onPostSuccess (data) {
      // 关闭弹出层
      this.isPostShow = false
      // 将发布内容显示到列表顶部
      this.commentList.unshift(data.new_obj)
    }

  }
}
</script>

<style scoped lang="less">
@import "./css/github-markdown.css";
.article-container {
  .main-wrap {
    padding-top: 92px;
    padding-bottom: 88px;
    overflow-y: scroll;
    background-color: #fff;
  }
  .article-detail {
    .article-title {
      font-size: 40px;
      padding: 50px 32px;
      margin: 0;
      color: #3a3a3a;
    }

    .user-info {
      padding: 0 32px;
      .avatar {
        width: 70px;
        height: 70px;
        margin-right: 17px;
      }
      .van-cell__label {
        margin-top: 0;
      }
      .user-name {
        font-size: 24px;
        color: #3a3a3a;
      }
      .publish-date {
        font-size: 23px;
        color: #b7b7b7;
      }
      .follow-btn {
        width: 170px;
        height: 58px;
      }
    }

    .article-content {
      padding: 55px 32px;
      /deep/ p {
        text-align: justify;
      }
    }
  }

  .loading-wrap {
    padding: 200px 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #fff;
  }

  .error-wrap {
    padding: 200px 32px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: #fff;
    .van-icon {
      font-size: 122px;
      color: #b4b4b4;
    }
    .text {
      font-size: 30px;
      color: #666666;
      margin: 33px 0 46px;
    }
    .retry-btn {
      width: 280px;
      height: 70px;
      line-height: 70px;
      border: 1px solid #c3c3c3;
      font-size: 30px;
      color: #666666;
    }
  }

  .article-bottom {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    justify-content: space-around;
    align-items: center;
    box-sizing: border-box;
    height: 88px;
    border-top: 1px solid #d8d8d8;
    background-color: #fff;
    .comment-btn {
      width: 282px;
      height: 46px;
      border: 2px solid #eeeeee;
      font-size: 30px;
      line-height: 46px;
      color: #a7a7a7;
    }
    .van-icon {
      font-size: 40px;
      .van-info {
        font-size: 16px;
        background-color: #e22829;
      }
    }
  }
}
</style>
